The present paper describes a new media access control protocol, called the multiple token protocol, for high-speed ring networks. The purpose of this protocol is to increase the throughput under a heavy load and to decrease the access delay under a light load ofthe token-ring protocol. The protocol maintains several logical token-rings in the single physical ring. The number of logical rings c...

Residual stresses (RS) in pipes welded by a fully automated friction welding process, called FRIEX, are investigated using the contour method (CM) and X-ray diffraction (XRD). Samples were produced self-developed equipment, which is based on interaction between consumable intermediate rotary ring two stationary pipe sections, varying loading rate applied during of API 5L B with an X65 ring. Mec...

A [4 + 4] annulation strategy for the synthesis of eight-membered carbocycles is reported that proceeds via a cascade involving two pericyclic processes. In the first step, the [4 + 2] cycloaddition of a conjugated enyne with an electron-deficient cyclobutene generates a strained six-membered cyclic allene that isomerizes to the corresponding 1,3-cyclohexadiene. In the second step, this bicyclo...

a two-year laboratory study on the biology (including self-fertilization) of bulinus truncatus, the intermediate host of schistosoma haematobium, s. bovis and paramphistomum microbotrium in iran, has revealed information on the longevity, reproduction, hatchability rate, hatching time during various months of the year, and growth and mortality rates of this snail. it was found that the reproduc...

The crystal structure of a colorless variant of green fluorescent protein (GFP) containing the Y66L substitution has been determined to 1.5 A. Crystallographic evidence is presented for the formation of a trapped intermediate on the pathway of chromophore maturation, where the peptide backbone of residues 65-67 has condensed to form a five-membered heterocyclic ring. The hydroxyl leaving group ...

Received ; accepted – 2 – ABSTRACT Among 330 normal spirals of types Sa-Sc the fraction of objects exhibiting " ring " , " intermediate " and " spiral " arm varieties does not correlated with environment. A similar conclusion appears to apply to the arm varieties of 123 barred spirals of types SBa-SBc. It is concluded that, among the northern Shapley-Ames galaxies, the distinction between the s...

We present an all-optical ring network architecture with logarithmic shortcuts and a systolic routing protocol for it. An r-dimensional optical ring network with logarithmic shortcuts (ORLS) consists of n = 2 nodes and r2 optical links. We study a systolic routing protocol that is based on cyclic changes of the states of routers and scheduled sendings of packets. The protocol ensures that no el...

A new forcefield model was developed for the computer simulation of phosphate materials that have many important applications in the electronics and biomedical industries. The model provides a fundamental basis for the evaluation of phosphate glass structure and thermodynamics. Molecular dynamics simulations of a series of lithium phosphate glass compositions were performed using the forcefield...